1. Field of the Invention
The present invention relates to a process for regenerating a catalyst of the type used in hydrocarbon conversion processes. More particularly, this invention relates to a process for regenerating a catalyst that has become deactivated or partially deactivated by the formation of stable, catalytically inert, complexes during contact with a hydrocarbon feedstock, said catalyst comprising (a) one or more Lewis acids selected from the group consisting of the fluorides, chlorides and bromides of boron(III), titanium(IV), zirconium(IV), hafnium(IV), hafnium(IV), phosphorus(V), arsenic(V), tantalum(V), niobium(V) and mixtures thereof and (b) a strong Bronsted acid, by contacting said catalyst with hydrogen at elevated temperatures and pressures.
2. Description of the Prior Art
It is well known in the prior art that the activity of Friedel-Craft's type hydrocarbon conversion catalysts declines gradually due to the accumulation of various contaminants or poisons, such as compounds of carbon, sulfur, nitrogen, oxygen, metals, water and the like, until the catalysts cease to exhibit an economic activity. In such cases, depending upon economic factors, the catalyst may be replaced or regenerated to restore desired activity levels.
Several methods have been suggested in the prior art for regenerating Friedel-Craft's type hydrocabon conversion catalysts via hydrogenation. For example, U.S. Pat. No. 3,173,881 teaches the reactivation of an aluminum halidehydrocarbon sludge by using hydrogen at elevated temperatures and pressures, preferably in the presence of a hydrogen halide. In addition, U.S. Pat. No. 3,352,941 teaches the regeneration of an aluminum halide supported catalyst with hydrogen at elevated temperatures and pressures wherein the hydrogen gas preferably includes a hydrogen halide corresponding to the particular aluminum halide used. Nonetheless, it is believed that none of the foregoing prior art discloses a method for regenerating the catalyst systems described hereinafter with hydrogen.